Vapor dispensing device



. 2, 1947.; s. JQDUNAWAY VAPOR DISPENSING DEVICE Filed Jan. 5, i946 w m($34, ".312? i I we 21,750 2": rd JDuzw wa y azjo 3 ZWJfnIZJM, 13441.44.I

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Patented Dec. 2, 1947 VAPOR DISPENSING DEVICE Sanford J. Dunaway, Dover,N. H., assignor to Judson Dunaway Corporation, Dover, N. H., acorporation of New Hampshire Application January 5, 1946, Serial No.639,473

4 Claims.

This invention relates to a vapor disp n vice intended for use as ameans for killing moths and moth worms, by the use of an evaporablemoth-killing substance such as paradichl-orobenzene existing in a solidstate within the cells of a carrying agent such as wall-board comprisingmatted woody fibers. The invention aims to provide a vapor dispensingdevice of this character with an evaporable indicating device whichshall indicate the extent of exhaustion of the evaporable substance inthe pores, so that replacement of the device may be made when it nolonger supplies sufficient vapor for the safe storage of woolens.

The invention will be understood by reference to the followingdescription when taken in connection with the accompanying drawings ofone specific embodiment thereof, While its scope will be pointed outmore particularly in the appended claims.

In the drawings:

Fig. l is an elevation of a vapor dispensing device embodying theinvention;

Fig. 2 is a sectional view on line 22 of Fig. l; and

Fig. 3 is a greatly enlarged sectional view of a portion of the carryingagent impregnated with the evaporable moth-killing substance.

Referring to the drawings and to the embodiment of the inventionillustrated therein as an example, there is shown a vapor dispensingdevice comprising a porous or pervious body 4 constituting a carryingagent for an evaporable substance 6 filling its pores. In the presentexample, the porous body is a slab of commercially obtainablefiber-board commonly known as Wall-board and comprising matted woodyfibers. The one chosen because of its suitability for the purpose issold under the trade-name Beaver Board and is so Well known that furtherdescription is deemed unnecessary.

The preferred evaporable substance 6 with which the body 4 isimpregnated is paradichlorobenzene commercially obtainable in the formof crystals, although naphthalene might be em ployed if desired. Theporous body 4 is impregnated with the desired substance, and is thenwrapped in a relatively impervious wrapper or jacket 8 such as a sealedenvelope or bag made of Cellophane. The preferred method of impregnatingthe body 4 with the paradichlorobenzene is to heat the latter to atemperature (around 53 C. or 135 F.) at which it melts, and thenimmersing the body in the molten paradichlorobenzene. When the lattercools, it re-crystalizes in the spaces between the fibers. (See Fig. 3.)It is found in practice that a rectangular piece of wallboard measuringthree by five inches and having a thickness of three-eighths of an inchwill take up two and one-half inches of paradichlo-robenzene, enough toprovide moth protection for fifteen cubic feet. After stripping off thewrapper, the slab may be hung on a hook or nail in a closet, chest, orother confined space where the woolens are stored, as by providing theslab with a hole l0. v

As the paradichlorobenzene within the cells of the slab is invisible, itis impossible for one to ascertain, by looking at the slab, whetherthere is any paradichlorobenzene present, and whether the slab should bereplaced by another fully charged slab. This problem is solved byproviding an evaporable indicator l2 whose rate of evaporation isproperly proportioned to the rate of evaporation from the pores of theslab, so that when the indicator is exhausted, or nearly so, the user iswarned that the slab should be replaced by a new, fully-charged slab.The best material for the indicator is paradichlorobenzene because itcontributes to the output of moth-killing vapor. Crystals can be meltedand molded to form a large lozenge-shaped mass or disk which can besnugly fitted into a hole I 4 in the slab 4, where it is easily visibleand serves as a warning device.

Having thus described one embodiment of the invention, what I claim is:

1. In a vapor dispensing device, the combination of a cellular carryingagent, an evaporable moth-killing substance existing in a solid statewithin the cells of said carrying agent, and an evaporable indicatorcarried by said agent without said cells.

2. In a vapor dispensing device, the combination of a cellular carryingagent provided with an opening, a moth-killing substance capable ofmelting at a temperature above room temperature, and capable ofevaporating at room temperature, and existing in a solid state in thecellular structure of said carrying agent, and an indicator within saidopening and capable of evaporating at room temperature.

3. In a vapor dispensing device, the combination of a slab of porousmaterial provided with an opening, a crystalline moth-killing substancecapable of evaporating at room temperature and existing in a crystallinesolid state in the pores of said slab, and an indicator consisting of asolid body of evaporable moth-killing subtsance with- 3 4 in saidopening and having a. rate of evaporation REFERENCES CITED comparablewith the first-named substance.

4. In a. vapor dispensing device, the combinag z $232213? erences are ofrecord in the tion of a body of woody fibers with minute intersticestherebetween, said body being provided 5 UNITED STATES PATENTS with anopening, paradichlorobenzene existing in Number Name Date a solid statewithin said interstices, and an in- 2303 073 Brown Nov 24 1942 dicatorconsisting of a, solid body of paradichloro- 1886429 Sacks 1932 benzeneWithin said 1:769:409 Armstn g fj jjjjj Ju1y 1, 1930 SANFORD DUNAWAY-2,069,179 Dunaway Jan.26,1937

